At 41, housewife Yuriko lives a peaceful, happy family life. But she harbors a secret even her husband doesn't know—by day, she's an ordinary homemaker; by night, she becomes the heroic warrior "Zendagirl," battling evil conspiracies. While her husband is at work, she dons her mask and chases down drug dealers as Zendagirl. Lately, a surge of juvenile crime known as "old man hunting" has swept the nation, and soon the threat reaches her own doorstep. Yuriko powerfully defeats the delinquent boys, but they plot revenge, bringing forth a new crisis. The battle between good and evil begins—not just to protect justice, but to safeguard her family's happiness.